1. Field of the Invention
The present invention relates generally to graph formats in computers, and more particularly to graph formats having multiple segments in computers having windowing systems.
2. Related Art
FIG. 1 illustrates a display image 102 associated with a computer system having a conventional windowing system. The computer image 102 may be either stored in a display memory or displayed on a display screen (or both). Included in the display image 102 are multiple windows 104. Each window contains one or more forms 106.
Each form 106 represents a rectangular area of pixels. A form 106 may be any size. Conventionally, forms 106 are considered to be indivisible elements by the windowing system. Consequently, whenever a screen update of a form is requested, the windowing system writes all of the pixels in the form to the display screen.
Conventionally, a graph is drawn on a single form (as illustrated by the form 106C). Adding a new point to the graph involves changing a few pixels in the form 106C. However, to display the new point on the display screen requires that all the pixels in the form 106C be written to the display screen, rather than just the pixels related to the new point.
Writing pixels to the display screen is very resource intensive. Thus, the conventional method for adding points to graphs represents a major burden on computer system resources. This is especially true in a real-time systems having Y-vs-time linegraphs.